JP5127765B2 - Pneumatic caisson composite shaft - Google Patents

Description

  The present invention relates to a composite shaft of a pneumatic caisson, and more particularly to a composite shaft in which a material shaft and a man shaft used in a pneumatic caisson method are integrated.

  Conventionally, in the construction of the pneumatic caisson method, the material shaft for transporting excavated sediment and machine materials and the operator's work are almost perpendicularly between the atmospheric pressure area above the ground and the high-pressure working room at the tip of the underground pneumatic caisson. There are man shafts for access, but these shafts can be provided separately if the pneumatic caisson has a large diameter. It can be used as a composite shaft or a common type that can also be used as a single shaft.

  FIG. 7A shows a cross-sectional view of an example of a conventionally used composite shaft. This composite shaft 20 is formed by forming a steel plate into an oval shape, and is formed as an oblong shape by a partition plate 21 that substantially crosses the center. The material shaft 23 is divided into two spaces, the other is a man shaft 24, the other is a man shaft 24, and the side walls of the composite shaft 20 are reinforced inside by reinforcing members 22a and 22b joined to both ends of the partition plate 21 (Patent Literature). 1). That is, the composite shaft 20 can be said to have a configuration in which a steel material having a H-shaped cross section is inserted and reinforced inside a cylindrical steel plate having a cross section of an ellipse. However, this configuration is not economical in that the steel plate is formed into an elliptical shape and that a reinforcing steel material is required inside.

  Another example of the conventional composite shaft is the composite shaft 30 shown in FIG. 7B, which is strengthened by forming reinforcing members to be bonded to both ends of the central partition plate 31 as the side wall plates 32 a and 32 b of the composite shaft 30, respectively. A die structure, and both end faces of a semi-cylindrical material shaft 33 and a man shaft 34 each having a semicircular cross section are joined to end faces on both sides of the side wall plates 32a and 32b of the H-type structure. It is configured to have an elliptical shape.

Japanese Utility Model Publication No. 4-15799

  When the ellipsoidal composite shaft of Patent Document 1 used in a pneumatic caisson having a relatively small diameter is used at a large depth, the atmospheric pressure in the high-pressure working chamber at the tip of the pneumatic caisson is increased in order to counter increasing groundwater pressure. Further, since the increased external pressure or internal pressure acts on the composite shaft that forms the bottom shaft adjacent to the working chamber, it is required to have a strong structure particularly on the oblong side wall portion. Regarding the external pressure acting on both the material shaft and the man shaft, although the cost is high, the composite shaft 20 that reinforces the side wall portion with an elliptical cylindrical body as an integral steel plate structure seems to be advantageous, but it further acts on the material shaft. No measures are taken against the internal pressure, which is not advantageous from the viewpoint of cost. In that respect, the composite shaft 30 mainly composed of the strengthened H-type structure is considered to exhibit high strength both in the external pressure and in the internal pressure, but the material shaft 33 and the man shaft 34 are formed of the semi-cylindrical body and the side wall plates 32a and 32b. It is disadvantageous to the increased internal / external pressure in that it is formed by joining the end faces. Accordingly, in order to use these composite shafts 20 to 30 at a deep depth position, further strength enhancement is required, which leads to further increase in weight and increase in manufacturing cost. Here, the conventional shared single shaft suggests a high pressure resistance of the cylindrical body, but a reliable integrated connection cannot be obtained simply by juxtaposing the two cylindrical bodies side by side.

  The present invention, therefore, solves the above-mentioned problems in the prior art, has a structure that can be used at a large depth in a relatively small-diameter pneumatic caisson, and can sufficiently withstand increasing internal and external pressures. It is an object of the present invention to provide a pneumatic caisson composite shaft that does not increase in weight and does not increase in manufacturing cost.

In order to achieve the above-mentioned object, the present invention according to claim 1 extends from the atmospheric pressure area above the ground to the high-pressure working room underground in the caisson housing of the pneumatic caisson method, and carries in and out excavated earth and sand. In a pneumatic caisson composite shaft consisting of a material shaft for maneuvering and a manshaft for raising and lowering workers, the material shaft and the manshaft are cylinders each having a circular cross section. A part of the circumference is overlapped with the circumference of the material shaft, and is combined with the material shaft that maintains a circular shape.
According to a second aspect of the present invention, in the composite shaft according to the first aspect, the man shaft is coupled to the outer peripheral surface of the material shaft at both side edges of the opening from which a part of the circumference is removed along the length direction. It is characterized by.
According to a third aspect of the present invention, there is provided the composite shaft according to the second aspect, wherein the joint portions of both side edges of the opening of the man shaft coupled to the outer peripheral surface of the material shaft are reinforced along the outer peripheral surfaces of both adjacent shafts. A reinforcing material is provided.

  According to the present invention, the material shaft and the man shaft constituting the composite shaft of the pneumatic caisson are each made of a cylindrical body, and the man shaft is part of the circumference of the material shaft within a range that does not reduce the strength of the cylindrical body. The material shaft that is subjected to both internal pressure and external pressure that increase at a deep depth position of the caisson housing maintains the circular shape in the most compact form. Man shafts that maintain maximum strength and receive only increasing external pressure can maintain the strength of almost perfect cylinders, and are manufactured with the weight reduction of composite shafts in that the steel plate can be made thinner than in the case of oblong type Cost can be reduced.

Sectional drawing which shows the structure of the composite shaft of the pneumatic caisson by this invention. The arrangement | positioning figure in the caisson housing of each part of the composite shaft of FIG. FIG. 3 is a plan view of a flange for coupling upper and lower ends between the composite intermediate shafts of FIG. 2. The top view of the flange which couple | bonds the compound anchor shaft of FIG. 2 with the anchor ring of an upper slab. FIG. 3 is a plan view of a flange for coupling the anchor ring of FIG. 2 to a composite anchor shaft. The fragmentary expanded sectional view which shows the coupling | bonding state between the anchor ring and composite anchor shaft in the upper slab of the pneumatic caisson of FIG. (A) is sectional drawing which shows an example of the structure of the composite shaft in a prior art. (B) is sectional drawing which shows the other example of the structure of the composite shaft in a prior art.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a cross-sectional structure common to a plurality of parts forming a composite shaft of a pneumatic caisson according to the present invention and sequentially arranged along the depth direction of the caisson housing, and FIG. The installation state at the time of use of each part of a composite shaft is shown.

  In FIG. 1, a composite shaft 1 of a pneumatic caisson according to the present invention has a material shaft 14 formed of a cylindrical body having a circular cross section, and also has a circular cross section, but a part of the circumference overlaps the circumference of the material shaft 14. It is comprised with the man shaft 15 which consists of a cylindrical body integrated with the material shaft 14 in the combined shape. The superposition on the circumference in this case is such that the material shaft 14 that receives air pressure that increases with increasing depth on the inner and outer surfaces maintains a perfect circular shape and maintains its strength, while the increased pressure is applied only to the outer surface. As for the man shaft 15 to be received, a part of the circumference is cut out, but the cutout is made such that the circular strength is substantially maintained. Actually, a part of the circumference is cut out along the length direction of the cylindrical body forming the man shaft 15 to form an axial opening, and both side edges of the opening are joined to the outer peripheral surface of the material shaft 14, for example, The composite shaft 1 is formed by integrally joining by welding. If necessary, a pair of reinforcing members 16 each having a wedge-shaped cross section are brought into contact with the adjacent outer peripheral surfaces of both shafts from the outside with respect to these two joint portions, and fixed by welding or joining to be coupled. Reinforce.

  Although the figure shows a configuration in which the diameter of the material shaft 14 is smaller than the diameter of the man shaft 15, the present invention is not limited to this configuration. That is, the figure shows that the diameter of the man shaft 15 can be increased as necessary. The material shaft and the man shaft can have the same diameter, or the material shaft can be opposite to the material shown in FIG. The diameter of the shaft can also be increased.

  In FIG. 2, a cylindrical or box-shaped caisson housing B forming a pneumatic caisson A is partitioned by a cutting edge E at a lower end edge and a working chamber slab C forming an inner bottom surface thereof, and is maintained at a high pressure. With D as the most advanced underground, the upper rear end opening is located outside the surface of the earth, and sinks with the progress of excavation in the working room D. An upper slab F is formed above the work chamber slab C, and a manlock G for waiting for an operator is provided between the two slabs so that the pressure can be controlled. That is, the worker once enters the manlock G from the lower end portion of the man shaft 15 described later, and enters and exits the work chamber D through an opening (not shown) penetrating the work chamber slab C. The working chamber slab C further includes an airtight opening H through which related machine materials such as a sand bucket 13 for excavating earth and sand and excavators pass, and a steel anchor ring 8 is provided on the peripheral surface of the opening H. A one-type hatch 9 for airtight construction is attached to the upper end of the anchor ring 8 that is fitted and located in the manlock G.

  In the manlock G above the one-type hatch 9, a composite bottom shaft 2 that is the lowest part of the composite shaft 1 formed by integrating the material shaft 14 and the man shaft 15 is installed, and the lower end of the material shaft 14 is Inserted into the one-type hatch 9, the lower end opening of the material shaft 14 is opened and closed by the hatch of the one-type hatch 9. The man shaft 15 of the composite bottom shaft 2 includes a pressure door 11 for entering and exiting an operator, and keeps the inside of the man shaft 15 at atmospheric pressure. Accordingly, the material shaft 14 in this manlock G is subjected to the action of high pressure on both the inner surface and the outer surface, and the man shaft 15 is subjected to the action of high pressure on the outer surface, so that the structure of the composite shaft 1 of the present invention shown in FIG. The effect is demonstrated.

  A steel anchor ring 10 having the same shape as the composite shaft 1 is fitted into the shaft insertion opening I of the upper slab F that partitions the upper portion of the manlock G. As shown in FIG. 5, an anchoring flange 10a including a material shaft side flange 14b and a man shaft side flange 15b is attached to the upper end of the anchor ring 10 by welding or the like. The composite anchor shaft 3 forming part of the composite shaft 1 is inserted into the anchor ring 10 and attached to the body of the composite anchor shaft 3 by welding or the like at a position above the anchor ring flange 10a. The shaft flange 3a is fixed to the anchoring flange 10a with a bolt or the like, and the upper portion thereof is reinforced with the reinforcing material 3b of the composite anchor shaft flange. The composite anchor shaft 3 is provided with a composite shaft flange 1a shown in FIG. 3 at the upper and lower ends, and is connected to the upper end of the composite bottom shaft 2 in the manlock G by bolts or the like at the lower flange 1a.

  Above the upper slab F, composite intermediate shafts 4a to 4n each forming a part of the composite shaft 1 are sequentially installed in the space inside the caisson housing B whose upper end opens on the ground surface as the caisson housing B sinks. . The composite intermediate shafts 4a to 4n have composite shaft flanges 1a shown in FIG. 3 at the upper and lower ends, respectively, and the upper and lower shafts are bolted to each other at the flanges 1a. A composite top shaft 5 is installed. In the composite top shaft 5, the material shaft 14 is provided with a material lock 7 having two hatches on the upper and lower sides via the different diameter shaft 6, and the man shaft 15 is provided with a door 12 for entering and leaving the worker.

  In the above configuration, each of the composite bottom shaft 2, the composite anchor shaft 3, the composite intermediate shafts 4a to 4n, and the composite top shaft 5 forming part of the composite shaft 1 is the material shaft 14 having the circular cross section described above with reference to FIG. Needless to say, the man shaft 15 has an integrally coupled structure.

  In the composite shaft 1, the interior of the man shaft 15 is maintained at atmospheric pressure, and although not shown, equipment for raising and lowering workers such as a ladder, a spiral staircase, and an elevator connecting the composite top shaft 5 and the composite bottom shaft 2 is provided. Prepare. The worker who has come out of the composite bottom shaft 2 to the manlock G passes through the one-type hatch for lifting and lowering the worker in the upper part of the steel anchor ring fitted into an opening (not shown) penetrating the work chamber slab C. Go in and out.

A Pneumatic caisson B Caisson housing C Working room slab D Working room E Blade edge F Upper slab G Manlock H Opening I Shaft insertion opening 1 Composite shaft 1a Composite shaft flange 2 Composite bottom shaft 3 Composite anchor shaft 3a Composite anchor shaft Flange 3b Composite anchor shaft flange reinforcement 4a-4n Composite intermediate shaft 5 Composite top shaft 6 Different diameter shaft 7 Material lock 8 Anchor ring 9 One-type hatch 10 Anchor ring 10a Anchoring flange 11 Worker inlet / outlet pressure air door 12 Worker entrance door 13 Earth and sand bucket 14 Material shaft 14a Material shaft flange 14b Anchoring material shaft side flange 15 Man shaft 15a Man shaft side flange 15b Ann -Ring for the man shaft flange 16 reinforcement

Claims (3)

The pneumatic caisson construction caisson enclosure extends from the atmospheric pressure range above the ground to the high-pressure working room, and is integrated with the material shaft for loading and unloading excavated sediment and machinery and the man shaft for lifting and lowering workers. In the composite shaft of pneumatic caisson consisting of structure,
The material shaft and the man shaft are each a cylinder with a circular cross section, and the man shaft is combined with the material shaft that maintains a circular shape by superimposing a part of the circumference on the circumference of the material shaft. Pneumatic caisson composite shaft characterized by   2. The composite shaft of a pneumatic caisson according to claim 1, wherein the man shaft is coupled to the outer peripheral surface of the material shaft at both side edges of the opening from which a part of the circumference is removed along the length direction. .   The new material according to claim 2, further comprising a reinforcing member that reinforces a joint portion of both side edges of the opening of the man shaft coupled to the outer peripheral surface of the material shaft along the outer peripheral surfaces of both adjacent shafts. Composite shaft of matic caisson.

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